Printing ink



Patented Dec. 14, 1943 7 PRINTING INK Donald Robert Erickson and Paul J.Thoma, Kalamazon, Mich, assignors to Michigan Research laboratories,Inc., Kalamazoo, Mich.

No Drawing. Application June 25, 1943,

Serial NG- 492,3Q

1 Claim. (01. 1015 30) This invention relates to improvements inprinting ink.

This invention is a continuation in part of application Serial No.396,296 flled'June' 2-, 1941, for Printing ink.

This invention relates to printing ink and particularly to the type ofink disclosed in United States Patent No. 2,244,103, issued June 3,1941, in which the binder comprises a resin comprising a rosin modifiedwith an alpha beta unsaturated organic polybasic acid such as maleic orfumaric' and the solvent consists of diethylene glycol or some otherliquid polyglycol and in which the application of water to the ink willprevent oilset but in whichthe ink will not set upon the press becauseof water tolerance due to the fact that the binder, which is insolublein water, is

soluble in the solvent and a limited quantity of water, but not in thesolvent with an unlimited quantity of water.

It has for its objects: First, to provide a new and improved printingSecond, to provide such-an ink which has im-'- proved and controllablewater tolerance in that the binder is soluble in the solvent with agreater quantity of water than in the caseof the ink oi theaforesaidtype. 1

Third, to provide such an ink which uses relatively inexpensivematerials and in which the addition of relatively more expensivematerials gives the desired result, thus keeping the cost oi! the ink ata minimum.

, ,Further objects and advantages pertaining to details will appear fromthe description to follow.

We have found that the water tolerance of an ink in which the varnish iscomposed of a resin comprising a rosin modified with an alpha beta highmolecular weight solid poly lycols in the ink in which diethylene glycolis used as a solvent than would be the caself the solvent were 'selectedfrom higher molecular weight liquid polyglycols, anda highly desirableincrease in water tolerance is thus obtained at a relatively low cost.

The addition of the high molecular weight solid polyglycols, inaddition. to tending to keep the me open longer on the press, also tendsto give better working bodies 0! the ink but does not appreciably cutdown the setting time for inks after they have been printed and aretreated with water, either in the form of sprays or steam in order toprevent offset.

We have found that from approximately to 10% of the high molecularweight polyglycols can be used and that by varying the amount the watertolerance can be-adjusted to suit the exact conditions and the type ofpress on whichthe'ink 4 is to be printed.

, An example of our invention consists in using 100 parts by weight 01'varnish made from 50% by weight of diethylene glycol and 50% by weightof a resin comprising a rosin modified with an' alpha beta unsaturatedorganic polybasic acid, such as maleic, as described in United StatesPatent 2,063,542, issued December 8, 1936, to Carleton Ellis, for Dieneresin. A suitable product is sold under the trade name "Teglac 127. Thisunsaturated organic polybasic acid such as maleic or iumaric and inwhich the solvent therefor consists of a liquid polyglycol such asdiethylene glycol or another relatively low molecular weight liquidpolyglycol may be increased so as to insure against setting up of theink on the press and to give extra and finer control of the ink forvarious climatic conditions by adding thereto small amounts of highmolecular weight polyglywater tolerance; It is less expensive to usethese inexpensive.- It has the desired properties as a material has ahigh acid number, .to-wit, about 300. The acid number of this productmay vary,

and run down as low as 200 and still give satisfactory results.

To this varnish we add 2 parts by weight of a solid polyglycol having amolecular weight of 1500. Such a polyglycol is sold under the trade aname Carbowax 1500."

Instead of using the polyglycol with molecli' .lar weight of 1500, wecan use other polyglycols with varying molecular weights, as long asthey are solid at room, temperatures, to 'give highlysatisfactoryresults. .For printing in very high relative humidity conditions or whenprinting by the dry oflset method whereink films are very thin, we canuse up to 10 of this solid polyglycol with very favorable results.

The above mentioned high molecular weight polyglycols are solid waxymaterials or the same general formula as the lower liquid polyglycolssuch as diethylene glycol.

In place 01' the diethylene glycol other liquid polyglycols can beusedas the solvent, although the diethylene glycol is readily availableandis Solvent in the printing ink.

Tothe varnishes above described, the desired quantity of pigment isadded. to by weight ofcarbon black may be added. 60% by weight of chromeyellow may be added. Other pigments may be used to give different colorand the, amounts will vary in' accordance with the colors andintensities desired.

The addition of the high molecular weight .solid. polygiycols isefi'eotive in the above varnishes. It is also efiective in inks made upof varnishes consisting of 80 parts of the above described varnish towhich may be added 20 parts of varnishes consisting of 50%. by weight ofdiethylene glycol and 50% by weight of phenolic resins such as thatwhich is sold under the trade name "Phenolic Resin 13109." The 20 partsof varnish may use as the binder also 50% by weight of gum'or woodrosin, or of urea-formaldehyde condensation product, ormelamine-formaldehyde condensation product, or a modified glycerolphthalate condensation product sold under the trade name "Rezyi 1145-51,or shellac.

To 80 parts of the first described varnishes, on may also add 20 partsofa varnish comprising 80% diethylene glycol and 20% of zein, or 80% ofdiethylene glycol and 20% of zein treated 'with an alpha betaunsaturated organic polybasic acid such as maleic or fumaric, or anorganic hydroxy acid.

In place of the binder comprising a rosin modifled with an alpha betaunsaturated organic polybasic acid such as'maleic or fumaric, one

may use a resin comprising a terpene hydrocarbon oi the formula CmHissuch as alpha terpinene, beta terpinene, pinene, alpha pinene. betapinene, dipentene, limonene, or terpinolene, re-

' acted with maleic or'fumaric acid. Suchaproduct may be obtained underthe trade name "Petrex Acid." v

It is also possible to use as the binder, mixtures of the resincomprising the rosin modified by the alpha beta unsaturated organicpolybasic acids and the terpene hydrocarbon of the formula C1oH1emodified by such an acid.

It is also possible to use the resin comprising the above mentionedmodified terpene hydrocarbon of the formula CmHie alone as the binder.

The terms and expressions which have been herein employed are used asterms of description and not of limitation. There is no intention in theuse of such terms of excluding any equivalents of the features shown anddescribed, or portions thereof. It is recognized that variousmodifications are possible within the scope of the invention claimed.

Having thus described our invention, what we claim as new and desire tosecure by Letters Patent is:

A non-offsetting printing inl; comprising 'avarnish comprising'a liquidpolyglycol as a solvent for the resin, a resin" as a binder selectedfrom the group consisting of rosin modified with an alpha betaunsaturated organic polybasic acid and a terpene hydrocarbon of theformula CioHie modified with an alpha beta unsaturated organic polybasicacid in sufllcient amount to form, when subjected to steam immediatelyafter printing, a thin hard film over the exposed surface of the,

printed film, from to 10% of a solid polya pigment insoluble in. water.

. DQNALD ROBERT ERICKSON. PAUL J. THOMA.

glycol, and

